This document provides an overview of social media channels and metrics. It discusses popular platforms like Facebook, Twitter, Instagram, YouTube, and LinkedIn. It examines the unique aspects of each channel including original features, prime posting times, and engagement habits. The document also defines common metrics used to measure audience engagement and evaluate the performance of social media campaigns. These include engagement ratio, growth ratio, link clicks, and earnings per click. It provides tips on collecting baseline metrics and reporting social media performance over time.